What is Java?

Java is a statically typed object-based programming language. Its ability to run on a virtual machine (Java virtual machine) makes it platform-independent (i.e. can be run on any device since it can be executed within a simulated virtual environment.)

What do we mean when we say statically typed? A statically-typed language is one coded with a rigid syntax, meaning when you define a variable, you have to specify from the outset what kind of data it will be assigned. Once declared, you won't be able to change this. This is a significant difference in both languages, as we will discover when we discuss JavaScript.

 

What is JavaScript?

On the other hand, JavaScript is a dynamically typed object-oriented scripting language that does not need to be set up or installed, unlike Java, because it runs within a computer's browser. Dynamically typed means any language with a more flexible syntax. You don't have to specify the type of data assigned to a variable because these can be changed or reassigned later. Javascript was designed as a scripting language to be relatively simple and lightweight. It was designed to work alongside CSS and HTML to achieve greater interactivity in the web browser experience.

It is perhaps easier to highlight the difference by looking at some sample code. Let's take a simple program to display Hello World in both Java and Javascript:

Java program to print "Hello World"

class xyz  
 {   
public static void main(String args[]){   
 System.out.println("Hello World");   
}   
}

JavaScript code to print "Hello World"

<!DOCTYPE html>  
<html>  
<body>  
<h2> JavaScript Sample Code</h2>  
<script type= "text/javascript">  
document.write("Hello World!");    
</script>  
</body>  
</html>

 

Java vs JavaScript: Key Differences

 

Execution(How to run)

While both programs output the words "hello world," you can only run the Javascript code through a browser. In contrast, the Java program can be compiled within a virtual environment, allowing it to be run on almost any machine independently of any other programs. You could run a Java program in your smart fridge. Javascript, however, needs an interpreter to run and has to be embedded in the HTML of a browser. This is one of the significant differences between both computer languages.

Complexity

As you can tell from the code snippets, Java is a more robust and complex language. This is necessary to maintain its ability to run independently of other programs. On the other hand, Javascript was designed to be lightweight but has sacrificed its independence to achieve that. With a much simpler syntax, it can produce the same results as a more complex programming language like Java but relies on an interpreter, i.e. the browser, for its execution.

Ease of Learning

Although Java is a more complex language than JavaScript, it is relatively easy to learn. As a scripting language that relies on a browser for execution, JavaScript was designed to be simple and lightweight. This allows the browser to execute the embedded scripts efficiently without too much strain on the user's internet connection. This helps to ensure a uniform browsing experience across geographical areas with different internet connection speeds. These differences play into their strengths; both were designed intentionally for those reasons. Because of its complexity, Java can be run independently across multiple platforms and hardware. Javascript, with its simplicity, can be run in lightweight applications like a browser.

File Extension

Though it might seem obvious, you don't want to spend hours wondering why your scripts or programs are not running, only to find that you've saved them with the wrong file extension. Java uses a .Java file extension, while javascript uses a .js file extension.

Support

Because it is a compiled and interpreted language, most devices with an operating system can run Java applications. Javascript approaches compatibility differently. As a scripting language, it was designed to be included among other types of code, such as HTML and CSS. This makes it more browser dependent regardless of the underlying operating system. The good thing is that most browsers support javascript.

Now that we've explored the key differences, let's examine how each language is used in tech.

 

Java Uses

Its status as a compiled language makes Java a robust option for building standalone applications. Some of Java's application scenarios include:

  1. Industrial and Enterprise Scale Development: Think about all the intelligent equipment you know, like factory production lines and large farm equipment. Though it rarely crosses our minds, those systems and machines are giant computers. They might not have the typical screen and interfaces we've come to associate with computers, but they are, and computers have to run programs to be helpful. Java is well-suited for writing programs for these systems as it can be compiled and run independently without relying on a browser to execute its code.
  2. Android Development: Similar to the reasons for its use in enterprise and industrial applications, Java is also particularly well-suited to android app development. There are many examples of JavaScript and browser-based games, even complex ones. However, to get the depth of interaction we've come to expect from our gaming experience and still have the ability to run uniformly across devices with different technical specifications, you will need to use a compiled language like Java.
  3. Back-End Server-side computing: Java has proved very useful in server-side backend programming. While you can get some interactivity with Javascript, any feature that needs more complexity has to be run on the server. This means the browser initiates the request while the program on the server processes and delivers the results back to the browser. Server-side programming is necessary because it allows developers to provide a uniform experience to users regardless of the computer spec of the user.
  4. Smart Devices and The Internet of Things: The world is becoming more connected. We have seen the introduction of many smart and connected devices in the last couple of years. These devices need to run programs to function and be connected to a network. Java's robust syntaxes and its independence make it the default choice to run these devices.

 

JavaScript Uses

Javascript was designed for the web and was intended to be lightweight and dynamically typed for flexibility. Its simple syntax allows it to be embedded within the HTML in most web browsers or just exported and linked to from a simple text file. These qualities make it great for the interactivity needed in today's websites. Some of the use cases for JavaScript include:

  1. Building dynamic and interactive web pages: JavaScript was designed to make web pages more dynamic and interactive. It is designed to work alongside other languages, such as HTML and CSS, to provide a richer and more immersive web experience. Creating and hiding menus, hover effects, zoom capabilities on images, and fancy menus like hamburger-style menus are all achieved using JavaScript.
  2. Building applications: JavaScript's large install base and support community have helped to push the boundaries on what is possible using this simple syntax language. With the use of JavaScript protocols such as React, React Native and Node.js, it is now possible to build mobile apps and achieve back-end development using JavaScript.
  3. Game Development: Though not as commonly used for game development as Java, there are a few popular games out there you would be surprised to learn were developed using JavaScript. Angry Birds and Bejewelled would be two famous examples. Developers are constantly expanding the possibilities of javascript-powered browser-based gaming.